Publications

• Structural insights into the catalytic mechanism of lovastatin hydrolase.

  Liang Y., Lu X.

  The lovastatin hydrolase PcEST from the fungus <i>Penicillium chrysogenum</i> exhibits enormous potential for industrial-scale applications in single-step production of monacolin J, the key precursor for synthesis of the cholesterol-lowering drug simvastatin. This enzyme specifically and efficient ... >> More

  The lovastatin hydrolase PcEST from the fungus <i>Penicillium chrysogenum</i> exhibits enormous potential for industrial-scale applications in single-step production of monacolin J, the key precursor for synthesis of the cholesterol-lowering drug simvastatin. This enzyme specifically and efficiently catalyzes the conversion of lovastatin to monacolin J but cannot hydrolyze simvastatin. Understanding the catalytic mechanism and the structure-function relationship of PcEST is therefore important for further lovastatin hydrolase screening, engineering, and commercial applications. Here, we solved four X-ray crystal structures, including apo PcEST (2.3 Å), PcEST in complex with monacolin J (2.48 Å), PcEST complexed with the substrate analog simvastatin (2.4 Å), and an inactivated PcEST variant (S57A) with the lovastatin substrate (2.3 Å). Structure-based biochemical analyses and mutagenesis assays revealed that the Ser⁵⁷ (nucleophile)-Tyr¹⁷⁰ (general base)-Lys⁶⁰ (general acid) catalytic triad, the hydrogen-bond network (Trp³⁴⁴ and Tyr¹²⁷) around the active site, and the specific substrate-binding tunnel together determine efficient and specific lovastatin hydrolysis by PcEST. Moreover, steric effects on nucleophilic attack caused by the 2',2-dimethybutyryl group of simvastatin resulted in no activity of PcEST on simvastatin. On the basis of structural comparisons, we propose several indicators to define lovastatin esterases. Furthermore, using structure-guided enzyme engineering, we developed a PcEST variant, D106A, having improved solubility and thermostability, suggesting a promising application of this variant in industrial processes. To our knowledge, this is the first report describing the mechanism and structure-function relationship of lovastatin hydrolase and providing insights that may guide rapid screening and engineering of additional lovastatin esterase variants. << Less

  J. Biol. Chem. 295:1047-1055(2020) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Single-step production of the simvastatin precursor monacolin J by engineering of an industrial strain of Aspergillus terreus.

  Huang X., Liang Y., Yang Y., Lu X.

  Monacolin J is a key precursor for the synthesis of simvastatin (Zocor), an important drug for treating hypercholesterolemia. Industrially, monacolin J is manufactured through alkaline hydrolysis of lovastatin, a fungal polyketide produced by Aspergillus terreus. Multistep chemical processes for t ... >> More

  Monacolin J is a key precursor for the synthesis of simvastatin (Zocor), an important drug for treating hypercholesterolemia. Industrially, monacolin J is manufactured through alkaline hydrolysis of lovastatin, a fungal polyketide produced by Aspergillus terreus. Multistep chemical processes for the conversion of lovastatin to simvastatin are laborious, cost expensive and environmentally unfriendly. A biocatalysis process for monacolin J conversion to simvastatin has been developed. However, direct bioproduction of monacolin J has not yet been achieved. Here, we identified a lovastatin hydrolase from Penicillium chrysogenum, which displays a 232-fold higher catalytic efficiency for the in vitro hydrolysis of lovastatin compared to a previously patented hydrolase, but no activity for simvastatin. Furthermore, we showed that an industrial A. terreus strain heterologously expressing this lovastatin hydrolase can produce monacolin J through single-step fermentation with high efficiency, approximately 95% of the biosynthesized lovastatin was hydrolyzed to monacolin J. Our results demonstrate a simple and green technical route for the production of monacolin J, which makes complete bioproduction of the cholesterol-lowering drug simvastatin feasible and promising. << Less

  Metab. Eng. 42:109-114(2017) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.